Buchholz, who has gone 2-4 with a 7.02 ERA in 10 starts this season, was placed on the DL May 28, two days after his last appearance, thanks to a hyperextended left knee.

He went 0-1 with a 2.53 earned run average in two rehab starts for Triple-A Pawtucket.

Last season, Buchholz went 12-1 with a 1.74 ERA in 16 regular season starts and earned his first All-Star appearance.

To make room on the roster, the Sox decided to part ways with the 35-year-old Capuano, who pitched to a 1-1 record and 4.55 ERA in 28 appearances. A native of western Massachusetts, Capuano was signed by Boston in late February.